Bergamaschi, B.A. and Hedges, J.I. (1995) A Multichambered Apparatus for HF Solvolysis Experiments - Reaction of Cellulose HF Solvolysis Products with Acetic-Acid and Acetic-Anhydride. Carbohydrate Research 267, 115-126. https://doi.org/10.1016/0008-6215(94)00279-O
Brian Bergamaschi
Biography
Dr. Brian Bergamaschi is a research biogeochemist with the USGS California Water Science Center and adjunct Faculty at California State University Sacramento. He received a Ph.D. in Chemical Oceanography from the University of Washington, in Seattle, WA, where he specialized in analyzing the sources and fates of natural organic material in the environment. His main interests are in understanding processes of carbon and nutrient cycling in aquatic environments and related biogeochemical processes. His particular interest is developing methods to quantify interactions between physical and biogeochemical processes. His research ranges in scale from light-mediated molecular transformations, to tidally driven wetland exchange, to effects of changing continental-scale nutrient fluxes on coastal carbon processes. His current projects largely focus on aquatic biogeochemical processes, aquatic habitat quality and carbon cycling in aquatic systems.
Science and Products
Date published: June 1, 2021
Status: Active Biogeochemistry Group
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Attribution: California Water Science Center
Date published: January 20, 2021
Status: Active Assessing Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta
Sediments represent an important pool of nutrients in the Sacramento-San Joaquin Delta (Delta). The exchange of nutrients between the water column and the benthos impacts water quality and effects phytoplankton, harmful algal blooms, aquatic vegetation, and drinking water quality. To date, there is very limited information about nutrient pools in Delta sediments, nor how these nutrients are...
Attribution: California Water Science Center
Date published: August 5, 2020
Status: Active Evaluating the effects of wastewater-derived nutrients on phytoplankton abundance and community structure in the San Francisco Estuary and Delta
Planned upgrades to the Sacramento Regional wastewater treatment plant (SRWTP) will substantially reduce nutrient discharge and also alter the types and amounts of nutrients being distributed across the San Francisco Delta and Estuary (Delta).
One highly anticipated outcome of lower nutrients is improved productivity in the phytoplankton communities that supply aquatic food webs, which...
Attribution: California Water Science Center
Date published: July 15, 2020
Status: Active Modeling Nitrogen Reduction Benefit to Invasive Aquatic Vegetation vs. Native Phytoplankton
Phytoplankton comprise the bottom of the aquatic food web and the abundance of phytoplankton serves as an indicator of healthy aquatic habitats. In the Sacramento-San Joaquin River Delta (Delta), competing with phytoplankton for required nitrogen, invasive aquatic vegetation (IAV) has increased exponentially in recent years. Once established, IAV can negatively impact local ecosystems and...
Attribution: California Water Science Center
Date published: November 22, 2019
Status: Active Creating a Model to Predict Future Carbon Levels in Tidally-driven Marshes
Tidal marshes are important ecosystems in the San Francisco-Bay Delta. They remove carbon from the atmosphere, they build up soils that buffer our communities from sea level rise, they provide critical habitat and food resources for a diversity of species, and they reduce excessive nutrients which have a negative impact on water quality. As a result of land-use change and urbanization, the San...
Attribution: California Water Science Center
Date published: March 2, 2019
Status: Active NASA-USGS National Blue Carbon Monitoring System
The NASA-USGS National Blue Carbon Monitoring System project will evaluate the relative uncertainty of iterative modeling approaches to estimate coastal wetland (marsh and mangrove) C stocks and fluxes based on changes in wetland distributions, using nationally available datasets (Landsat) and as well as finer scale satellite and field derived data in six sentinel sites.
Contacts: Lisamarie Windham-Myers
Attribution: Water Resources
Date published: December 10, 2018
Status: Completed Trends in Dissolved Organic Carbon (DOC) in the Sacramento-San Joaquin Delta
Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water treatment process. The amount of DBPs that form is a function of both the amount and source of the DOC, both...
Contacts: Brian Bergamaschi, Tamara Kraus
Attribution: California Water Science Center
Date published: December 6, 2018
Status: Completed Methylmercury and Low Dissolved Oxygen Events in Suisun Marsh
The primary purpose of the USGS portion of this proposed study is to evaluate if spectrophotometric and spectrofluorometric methods are useful for identifying organic sources of oxygen demand by analyzing water-quality samples (DO, BOD, Chl, SSC, Salinity, THg, MeHg) collected by other agencies and project participants. Sources to be evaluated include algal production, vegetation, soils, and...
Contacts: Brian Bergamaschi
Attribution: California Water Science Center
Date published: December 6, 2018
Status: Completed Mercury and Dissolved Organic Matter in Delta Wetlands
Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar,...
Contacts: Brian Bergamaschi, Jacob A Fleck
Attribution: California Water Science Center
Date published: December 4, 2018
Status: Completed Sources of Disinfection Byproduct-forming Material in the State Water Project
Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water-treatment process. The amount of DBPs that form is a function of the amount and source of the DOC, both of...
Contacts: Brian Bergamaschi
Attribution: California Water Science Center
Date published: November 15, 2018
Status: Completed High-Speed Mapping of Nutrient Distributions and Water Quality Survey - Lower South San Francisco Bay
This project aims to characterize spatial heterogeneity for key water quality parameters, and pilot the use of underway-flowthrough mapping of biogeochemical properties as a cost-effective approach to monitoring.
Contacts: Brian Bergamaschi
Attribution: California Water Science Center
Date published: November 15, 2018
Status: Active Dynamics of zooplankton in the Cache Slough Complex
Our purpose is to investigate what controls the distribution and abundance of fish prey within the Cache Slough Complex (CSC).
Contacts: Brian Bergamaschi
Attribution: California Water Science Center
Year Published: 2020
Tidal wetland gross primary production across the continental United States, 2000–2019
We mapped tidal wetland gross primary production (GPP) with unprecedented detail for multiple wetland types across the continental United States (CONUS) at 16‐day intervals for the years 2000–2019. To accomplish this task, we developed the spatially explicit Blue Carbon (BC) model, which combined tidal wetland cover and field‐based eddy covariance...
Feagin, R.A.; Forbrich, I.; Huff, T. P.; Barr, J.G.; Ruiz-Plancarte, J.; Fuentes, J.D.; Najjar, R.G.; Vargas, R.; Vazquez Lule, A.; Windham-Myers, L.; Kroeger, Kevin D.; Ward, E. J.; Moore, G.W.; Leclerc, M.; Krauss, K.W.; Stagg, C.L.; Alber, M.; Knox, S. H.; Schafer, K. V. R.; Bianchi, T.S.; Hutchings, J. A.; Nahrawi, H.; Noormets, A.; Mitra, B.; Jaimes, A.; Hinson, A.L.; Bergamaschi, Brian; King, J.S.; Miao, G.
Year Published: 2020
Spatial variability of phytoplankton in a shallow tidal freshwater system reveals complex controls on abundance and community structure
Estuaries worldwide are undergoing changes to patterns of aquatic productivity because of human activities that alter flow, impact sediment delivery and thus the light field, and contribute nutrients and contaminants like pesticides and metals. These changes can influence phytoplankton communities, which in turn can alter estuarine food webs. We...
Stumpner, Elizabeth; Bergamaschi, Brian; Kraus, Tamara E. C.; Parker, Alexander; Wilkerson, Francis; Downing, Bryan D.; Dugdale, Richard; Murrell, Michael T.; Carpenter, Kurt; Orlando, James; Kendall, Carol
Year Published: 2019
The use of stable isotope-based water age to evaluate a hydrodynamic model
Transport time scales are common metrics of the strength of transport processes. Water age is the time elapsed since water from a specific source has entered a study area. An observational method to estimate water age relies on the progressive concentration of the heavier isotopes of hydrogen and oxygen in water that occurs during evaporation. The...
Gross, Edward; Andrews, Stephen; Bergamaschi, Brian; Downing, Bryan D.; Holleman, Rusty; Burdick, Scott; Durand, JohnAttribution: California Water Science Center, Water Resources
Year Published: 2019
Direct and indirect effects of tides on ecosystem-scale CO2 exchange in a brackish tidal marsh in Northern California
We investigated the direct and indirect influence of tides on net ecosystem exchange (NEE) of carbon dioxide (CO2) in a temperate brackish tidal marsh. NEE displayed a tidally driven pattern with obvious characteristics at the multiday scale, with greater net CO2uptake during spring tides than neap tides. Based on the relative mutual information...
Sara Knox; Windham-Myers, Lisamarie; Frank Anderson; Cove Sturtevant; Bergamaschi, BrianAttribution: California Water Science Center, Water Resources
Year Published: 2018
Potential for negative emissions of greenhouse gases (CO2, CH4 and N2O) through coastal peatland re-establishment: Novel insights from high frequency flux data at meter and kilometer scales
High productivity temperate wetlands that accrete peat via belowground biomass (peatlands) may be managed for climate mitigation benefits due to their global distribution and notably negative emissions of atmospheric carbon dioxide (CO2) through rapid storage of carbon (C) in anoxic soils. Net emissions of additional greenhouse gases (GHG)—methane...
Windham-Myers, Lisamarie; Bergamaschi, Brian; Anderson, Frank A.; Knox, Sarah; Miller, Robin; Fujii, RogerAttribution: Water Resources
Year Published: 2018
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by...
Hansen, Angela M.; Fleck, Jacob; Kraus, Tamara E. C.; Downing, Bryan D.; von Dessonneck, Travis; Bergamaschi, BrianAttribution: California Water Science Center, Water Resources, United States of America, Laboratories, Organic Matter Research Laboratory
View Citation
Hansen, A.M., Fleck, J.A., Kraus, T.E.C., Downing, B.D., von Dessonneck, T., and Bergamaschi, B.A., 2018, Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter: U.S. Geological Survey Open-File Report 2018–1096, 31 p., https://doi.org/10.3133/ofr20181096.
Year Published: 2017
Using paired in situ high frequency nitrate measurements to better understand controls on nitrate concentrations and estimate nitrification rates in a wastewater-impacted river
We used paired continuous nitrate ( ) measurements along a tidally affected river receiving wastewater discharge rich in ammonium ( ) to quantify rates of change in concentration ( ) and estimate nitrification rates. sensors were deployed 30 km apart in the Sacramento River, California (USA), with the upstream...
Kraus, Tamara E. C.; O'Donnell, Katy; Downing, Bryan D.; Burau, Jon R.; Bergamaschi, BrianView Citation
Kraus, T. E. C., O'Donnell, K., Downing, B.D., Burau, J.R. and Bergamaschi, B.A., 2017, Using paired in situ high frequency nitrate measurements to better understand controls on nitrate concentrations and estimate nitrification rates in a wastewater-impacted river: Water Resources Research, v. 53, p. 1-20, https://doi.org/10.1002/2017WR020670.
[First online 13 Sept. 2017]
Year Published: 2017
Irrigation as a fuel pump to freshwater ecosystems
We generated a detailed time series of total dissolved hydrolyzable amino acids (DHAA) in a watershed dominated by irrigated agriculture in northern California, USA to investigate the roles of hydrologic and seasonal changes on the composition of dissolved organic matter (DOM). DHAA are sensitive indicators of the degradation state and reactivity...
Matiasek, Sandrine; Pellerin, Brian A.; Spencer, Robert G.M.; Bergamaschi, Brian; Hernes, Peter J.Attribution: Water Resources
View Citation
Matiasek SJ, BA Pellerin, RGM Spencer, BA Bergamaschi, and PJ Hernes. 2017. Irrigation as a fuel pump to freshwater ecosystems. Biogeochemistry, 136:71-90.
Year Published: 2017
An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the first in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). This first report provides an introduction to the reasons for and fundamental concepts behind collecting HF measurements...
Kraus, Tamara E.C.; Bergamaschi, Brian A.; Downing, Bryan D.View Citation
Kraus, T.E.C., Bergamaschi, B.A., and Downing, B.D., 2017, An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California: U.S. Geological Survey Scientific Investigations Report 2017–5071, 41 p., https://doi.org/10.3133/sir20175071.
Year Published: 2017
Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the third in a series of three reports that provide information about how high-frequency (HF) nutrient monitoring may be used to assess nutrient inputs and dynamics in the Sacramento–San Joaquin Delta, California (Delta). The purpose of this report is to provide the background, principles, and considerations for...
Bergamaschi, Brian A.; Downing, Bryan D.; Kraus, Tamara E.C.; Pellerin, Brian A.View Citation
Bergamaschi, B.A., Downing, B.D., Kraus, T.E.C., and Pellerin, B.A., 2017, Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California: U.S. Geological Survey Scientific Investigations Report 2017–5058, 40 p., https://doi.org/10.3133/sir20175058.
Year Published: 2017
Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). The purpose of this report is to synthesize the data available from a nutrient and water-quality HF (about every 15...
Downing, Bryan D.; Bergamaschi, Brian A.; Kraus, Tamara E.C.View Citation
Downing, B.D., Bergamaschi, B.A., and Kraus, T.E.C., 2017, Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California: U.S. Geological Survey Scientific Investigations Report 2017–5066, 28 p., https://doi.org/10.3133/sir20175066.
Year Published: 2017
A river-scale Lagrangian experiment examining controls on phytoplankton dynamics in the presence and absence of treated wastewater effluent high in ammonium
Phytoplankton are critical component of the food web in most large rivers and estuaries, and thus identifying dominant controls on phytoplankton abundance and species composition is important to scientists, managers, and policymakers. Recent studies from a variety of systems indicate that ammonium ( NH+4) in treated wastewater effluent decreases...
Kraus, Tamara E. C.; Carpenter, Kurt; Bergamaschi, Brian; Parker, Alexander; Stumpner, Elizabeth; Downing, Bryan D.; Travis, Nicole; Wilkerson, Frances; Kendall, Carol; Mussen, TimothyPre-USGS Publications
Hedges, J.I., Bergamaschi, B.A. and Benner, R. (1994) Comparative Analyses of DOC and DON in Natural Water - Erratum (Vol 41, Pg 121, 1989). Marine Chemistry 46, 407-408. https://doi.org/10.1016/0304-4203(94)90035-3
Hedges, J.I., Bergamaschi, B.A. and Benner, R. (1993) Comparative Analyses of DOC and DON in Natural Water. Marine Chemistry 41, 121-134. https://doi.org/10.1016/0304-4203(93)90110-A
Hopkinson, C., Cifuentes, L., Burdige, D., Fitzwater, S., Hansell, D., Henrichs, S., Kahler, P., Koike, I., Walsh, T. and Bergamaschi, B. (1993) Measurement of Dissolved Organic Carbon and Nitrogen in Natural Waters - DON Subgroup Report. Marine Chemistry 41, 23-36. https://doi.org/10.1016/0304-4203(93)90103-U
Hedges, J.I. and Bergamaschi, B.A. (1992) Seawater Carbon Measurement. Nature 359, 202-202. https://doi.org/DOI 10.1038/359202a0
Date published: July 16, 2021
CAWSC Biogeochemistry Group Expands its Monitoring of Water Quality in the Delta
The USGS California Water Science Center’s Biogeochemistry Group continues to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Attribution: California Water Science Center
Date published: January 29, 2021
Scientists Assess Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta
California Water Science Center scientists have begun the first comprehensive assessment of sediment nutrient inventories and fluxes in the Sacramento-San Joaquin Delta (Delta). Their findings will serve as a baseline for assessing water quality improvements following upcoming upgrades to the Sacramento Regional Wastewater Treatment Plant and wetland restoration efforts.
Attribution: California Water Science Center